Thomas Anglmaier
2009-Jun-03  10:49 UTC
[Samba] all connections closed if user gives wrong pwd (#long posting inside)
Hi list,
i have a problem mounting shares on a single client with diffrent usernames. if
any user on the client gives a wrong password all existing cifs mounts are
closed by the server.
Since this problem occured in a productive environment i set up a testing env
and tried to keep it as easy as can be:
Servername: serverA
Servicename1: home1
Servicename2: home2
Clientname: clientA
Username1: tom
Username2: max
Linux Distribution (Server+Client): Red Hat Enterprise Linux Server release 5.3
(Tikanga)
Kernel (Server+Client): 2.6.18-128.1.10.el5 (also tested on: 2.6.26-2 and
2.6.18-92.1.18.el5)
Samba version: 3.0.33-3.7.el5 (also tested on: 3.2.5)
cifs module version: 1.54RH (also tested on: 1.53 and 1.50cRH)
I can reproduce this issue on Debian, SuSE and Redhat Linux. (these are the ones
i've tested)
Here is what the users do:
.) ssh root@clientA
.) mount -t cifs -o user=tom //serverA/home1 /mnt/1/
        #users gives correct password and "home1" gets mounted just
fine
.) mount -t cifs -o user=max //tofo1/home2 /mnt/2
        #user gives correct password and "home2" gets mounted just
fine
        #but if user "max" gives a wrong password all existing
connections are closed by the server
screendump of the above sequence:
###############################################
[root@clientA ~]# df -ha
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1             7.6G  2.4G  4.8G  34% /
proc                     0     0     0   -  /proc
sysfs                    0     0     0   -  /sys
devpts                   0     0     0   -  /dev/pts
tmpfs                 125M     0  125M   0% /dev/shm
none                     0     0     0   -  /proc/sys/fs/binfmt_misc
sunrpc                   0     0     0   -  /var/lib/nfs/rpc_pipefs
[root@clientA ~]#  mount -t cifs -o user=tom //serverA/home1 /mnt/1/
Password:       #correct password given
[root@clientA ~]# df -ha
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1             7.6G  2.4G  4.8G  34% /
proc                     0     0     0   -  /proc
sysfs                    0     0     0   -  /sys
devpts                   0     0     0   -  /dev/pts
tmpfs                 125M     0  125M   0% /dev/shm
none                     0     0     0   -  /proc/sys/fs/binfmt_misc
sunrpc                   0     0     0   -  /var/lib/nfs/rpc_pipefs
//serverA/home1         7.6G  2.5G  4.8G  35% /mnt/1
root@clientA ~]#  mount -t cifs -o user=max //serverA/home2 /mnt/2
Password:       #wrong password given
mount error 13 = Permission denied
Refer to the mount.cifs(8) manual page (e.g.man mount.cifs)
[root@clientA ~]# df -ha
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1             7.6G  2.4G  4.8G  34% /
proc                     0     0     0   -  /proc
sysfs                    0     0     0   -  /sys
devpts                   0     0     0   -  /dev/pts
tmpfs                 125M     0  125M   0% /dev/shm
none                     0     0     0   -  /proc/sys/fs/binfmt_misc
sunrpc                   0     0     0   -  /var/lib/nfs/rpc_pipefs
//serverA/home1         0.0K  0.0K  0.0K   -  /mnt/1
[root@clientA ~]# stat /mnt/1
stat: cannot stat `/mnt/1': Input/output error
[root@clientA ~]#
#####################################################
#/etc/samba/smb.conf
[global]
        workgroup = MYGROUP
        server string = Samba Server Version %v
        log file = /var/log/samba/tst.log
        log level = 3
        security = user
        passdb backend = tdbsam
[home1]
        comment = Public Stuff
        path = /home/1
        write list = tom max hugo
        browsable = yes
        [home2]
        comment = Public Stuff
        path = /home/2
        write list = tom max hugo
        browsable = yes
#/var/log/samba/tst.log
[2009/06/03 14:37:02, 2] auth/auth.c:check_ntlm_password(319)
  check_ntlm_password:  Authentication for user [max] -> [max] FAILED with
error NT_STATUS_WRONG_PASSWORD
[2009/06/03 14:37:02, 3] smbd/error.c:error_packet_set(106)
  error packet at smbd/sesssetup.c(1501) cmd=115 (SMBsesssetupX)
NT_STATUS_LOGON_FAILURE
[2009/06/03 14:37:02, 3] smbd/process.c:timeout_processing(1329)
  timeout_processing: End of file from client (client has disconnected).
[2009/06/03 14:37:02, 3] smbd/sec_ctx.c:set_sec_ctx(241)
  setting sec ctx (0, 0) - sec_ctx_stack_ndx = 0
[2009/06/03 14:37:02, 3] smbd/sec_ctx.c:set_sec_ctx(241)
  setting sec ctx (0, 0) - sec_ctx_stack_ndx = 0
[2009/06/03 14:37:02, 1] smbd/service.c:close_cnum(1230)
  192.168.0.21 (192.168.0.21) closed connection to service home1
[2009/06/03 14:37:02, 3] smbd/connection.c:yield_connection(69)
  Yielding connection to home1
[2009/06/03 14:37:02, 3] smbd/sec_ctx.c:set_sec_ctx(241)
  setting sec ctx (0, 0) - sec_ctx_stack_ndx = 0
[2009/06/03 14:37:02, 3] smbd/connection.c:yield_connection(69)
  Yielding connection to
[2009/06/03 14:37:02, 3] smbd/server.c:exit_server_common(768)
For me this looks like as smb closes the connection to home1
"gracefully". As it would be usual behaviour.
I am really stuck on this issue since i've allready tried everything that
hops to my mind.
Hopefully someone can point me in the right direction or has had a similar
problem.
Please bear with my english. It's not my mother tongue.
Thanks in advance
Thomas
Thomas Anglmaier
2009-Jun-04  10:04 UTC
[Samba] all connections closed if user gives wrong pwd (#long posting inside)
reply to my own post: a little bit of more research on the server side and reading cifs documentation let me point out the problem: cifs.ko starts a thread (cifsd) for each connection to a server. this thread is killed if a user gives a wrong password which means every mounted cifs-share is gone. $ echo 1 > /proc/fs/cifs/cifsFYI #gives good information after doing what was described in my last post. dmesg | grep kill fs/cifs/connect.c: cifsd thread killed so this means it is not related to samba but to the cifs module. hope this helps anyone. br thomas